我在大学里修了一门java课程，其中一个家庭作业是写一个程序，读取一个0到100（含）之间的整数，代表购买的金额。我遇到的问题是if-else语句。每次编译时，都会说小于等号是非法的类型开头。有人能给我解释一下为什么会这样，我怎么能修好它？提前谢谢！

import java.util.Scanner;

    public class RefundAmount {

       public static void main(String [] args) {
        Scanner scan = new Scanner (System.in);

        int change;
        int dollars, quarters, dimes, nickels, pennies;

        System.out.println("Enter the purchase price [0-100]: ");
              int price = scan.nextInt();

        System.out.println("Enter the amount paid: ");
              int paid = scan.nextInt();

        change = price - paid;

        dollars = (change / 100);
        change = change % 100;
        quarters = (change / 25);
        change = change % 25;
        dimes = (change / 10);
        change = change % 10;
        nickels = (change / 5);
        change = change % 5;
        pennies =  change;

        if (change >= 0 || <= 100){

        System.out.print("Your change of " + purchase + " cents is given as:");
     }else
        System.out.println("Purchase must between 0 and 100 cents.");

        System.out.println(" " + dollars + " dollars");
        System.out.println(" " + quarters + " Quarters");
        System.out.println(" " + dimes + " Dimes");
        System.out.println(" " + nickels + " Nickels");
        System.out.println(" " + pennies + " Pennies");

     }
    }